SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier a
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t (alias t1)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier t (alias t2)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t1.a
        Identifier t2.a
   Identifier t1.a
